Power Adjustment Device

One aspect of the present disclosure relates to a power adjustment device that adjusts a power supply and demand balance.

The following Patent Literature 1 discloses an independent power supply system that calculates demand forecast data for a load device and power generation output forecast data for a natural energy power generator using weather forecast data and that suppresses the power generation output from the natural energy power generator when it is predicted that the storage battery will be charged beyond its maximum charge power based on the demand forecast data and the power generation output forecast data and suppresses the power consumption of an adjustment load when it is predicted that the storage battery will be discharged beyond its maximum discharge power based on the demand forecast data and the power generation output data.

In the independent power supply system described above, the storage battery for the charging and discharging of power and the adjustment load that adjusts power consumption are fixed. For this reason, it may not be possible to appropriately adjust the power supply and demand balance. Therefore, there is a demand for technology that can appropriately adjust the power supply and demand balance.

A power adjustment device according to one aspect of the present disclosure is a power adjustment device for adjusting a supply and demand balance of power in a power system including one or more power devices each of which is at least one of a storage battery and a load, and includes: a setting unit that sets at least one of the power devices as a target power device, for which operation control related to power is possible, based on the supply and demand balance predicted; and an adjustment unit that adjusts the supply and demand balance by controlling an operation of the target power device.

According to this aspect, it is possible to set target power devices whose operations are to be controlled in order to adjust the supply and demand balance, based on the predicted power supply and demand balance. Therefore, it is possible to appropriately adjust the power supply and demand balance.

According to one aspect of the present disclosure, it is possible to appropriately adjust the power supply and demand balance.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the diagrams. In addition, in the description of the diagrams, the same elements are denoted by the same reference numerals, and repeated description thereof will be omitted. In addition, the embodiments of the present disclosure in the following description are specific examples of the present invention, and the present invention is not limited to these embodiments unless there is a statement that specifically limits the present invention.

is a diagram showing an example of the system configuration of a power system including a power adjustment device according to an embodiment. As shown in, a power systemincludes a power adjustment device, one or more control devices, one or more storage batteries, one or more loads, and one or more power supply sources. In the present embodiment, a plurality of control devices, a plurality of storage batteries, a plurality of loads, and a plurality of power supply sourceswill be collectively referred to simply as “control device”, “storage battery”, “load”, and “power supply source”, respectively, as appropriate. The control device, the storage battery, and the loadare provided, for example, in a customer facility. The customer facility may be a home, an office building, a store, or other facilities. The power systemincludes one or more power devices. The power device is at least one of the storage batteryand the load. In the example shown in, the power systemincludes one or more power devices. In the present embodiment, a plurality of power devices will be collectively referred to simply as “power device” as appropriate.

The power adjustment deviceadjusts a power supply and demand balance in the power system. The power supply and demand balance is the relationship, equilibrium, balance, or harmony between the power that is scheduled to be supplied to the power system(supply power) and the power that is predicted to be demanded in the power system(demand power). The supply power may be, for example, power provided by a power supply source. The demand power may be, for example, the power consumed by the load. The power adjustment devicewill be described in detail later.

The control deviceis communicably connected to the power adjustment device, and controls the operation of the power device based on a control command received from the power adjustment device. For example, the control devicecontrols the charging and discharging of the storage batteryand the operating state of the loadbased on a control command received from the power adjustment device. The control of the operating state of the loadincludes not only control for activating the loadand control for deactivating the loadbut also control for changing the output of the load.

The storage batteryis a power device that performs charging and discharging of power. The storage batteryis electrically connected to the power supply sourceand accordingly, can be charged with power supplied from the power supply source. In addition, the storage batteryis electrically connected to the loadand accordingly, can discharge the power charged in itself to supply the power to the load.

The loadis a power device that consumes power for its own operation. The loadcan be operated by power supplied from the power supply sourceand power supplied from the storage battery. The loadmay be, for example, an air conditioner, a lighting device, or OA equipment.

The power supply sourceis a source of power supplied to the power system. The power supplied from the power supply sourceis consumed, for example, in the load. The power supplied from the power supply sourcemay be charged into the storage battery. The power supply sourcemay be, for example, a commercial power source. When the power supply sourceis a commercial power source that generates AC current, the power systemmay further include a rectifier (not shown) that converts the AC power from the power supply sourceinto DC power and outputs the DC power. The power systemmay further include a smart meter. The smart meter is a power meter that can measure the power consumption in the power systemand transmit the measured data to a remote device (for example, a server of a power supplier that manages the power supply source) using the device's own communication function.

An overview of processing for adjusting the power supply and demand balance by the power adjustment devicewill be described. First, the power adjustment devicepredicts the power supply and demand balance for a future target period. The power adjustment devicepredicts the power supply and demand balance based on, for example, a difference between demand power and supply power. The supply and demand balance prediction process will be described in detail later.

When it is predicted that an abnormality in the power supply and demand balance will occur, the power adjustment deviceperforms operation control related to the power of the target power device in the period in which the abnormality is predicted to occur. The term “target power device” refers to a power device for which operation control related to power is possible, and is used to adjust the supply and demand balance. “Operation control related to the power of the target power device” refers to control for adjusting the power supply and demand balance. For example, “operation control related to the power of the target power device” refers to control related to discharging or charging of the storage batterywhen the power device is the storage battery, and refers to control of the operating state of the loadwhen the power device is the load. The power adjustment devicesets a target power device among a plurality of power devices based on the predicted supply and demand balance. For example, the power adjustment devicesets a target power device among a plurality of power devices so that the abnormality in the supply and demand balance can be resolved. The process of setting the target power device will be described in detail later.

When overdemand for power is predicted, the power adjustment devicetransmits to the control deviceat least one of a control command to discharge the storage batteryset as a target power device in the period in which overdemand is predicted and a control command to deactivate the loadset as a target power device. In contrast, when the oversupply of power is predicted, the power adjustment devicetransmits to the control deviceat least one of a control command to charge the storage batteryset as a target power device and a control command to activate the loadset as a target power device in the period in which the oversupply is predicted. The control deviceadjusts the supply and demand balance by controlling the storage batteryand the loadbased on the control command received from the power adjustment device, thereby avoiding the occurrence of an abnormality in the supply and demand balance.

is a diagram showing an example of the functional configuration of the power adjustment device according to the embodiment. As shown in, the power adjustment deviceincludes a storage unit, a prediction unit, a setting unit, and an adjustment unit.

Each functional block of the power adjustment deviceis assumed to function within the power adjustment device, but the present invention is not limited thereto. For example, some of the functional blocks of the power adjustment devicemay function within a computer device, which is different from the power adjustment deviceand is connected to the power adjustment devicethrough a network, while appropriately transmitting and receiving information to and from the power adjustment device. In addition, some of the functional blocks of the power adjustment devicemay be omitted, a plurality of functional blocks may be integrated into one functional block, or one functional block may be divided into a plurality of functional blocks.

Hereinafter, each function of the power adjustment deviceshown inwill be described.

The storage unitstores any information used in the calculations and the like in the power adjustment device, results of the calculations in the power adjustment device, and the like. The information stored in the storage unitmay be referred to by each functional element of the power adjustment deviceas appropriate.

The prediction unitpredicts the power supply and demand balance in the power system. The prediction unitpredicts the supply and demand balance based on, for example, demand power and supply power.

The setting unitsets at least one power device among the power devices included in the power system, as a target power device, based on the predicted supply and demand balance.

When the occurrence of an abnormality in the supply and demand balance is predicted, the setting unitmay set the target power device so that the abnormality in the supply and demand balance can be resolved.

The setting unitmay set the target power device so that the adjustment power amount that can be adjusted by controlling the operation of the target power device is equal to or greater than the differential power amount, which is the difference between the supply power scheduled to be supplied to the power systemand the demand power predicted to occur in the power system.

The setting unitmay set the target power device so that the difference between the adjustment power amount and the differential power amount is minimized.

The setting unitmay set the target power device based on at least one of the amount of power charged and discharged in the storage batteryand the amount of power consumed by the load.

The setting unitmay set one or more storage batteriesand one or more loadsas target power devices.

The setting unitmay determine whether or not to set the loadas a target power device based on the operating state of the load.

The setting unitmay set the target power device based on an instruction from the user of the power adjustment device.

The adjustment unitadjusts the supply and demand balance by controlling the operation of the target power device. “Performing operation control of the target power device” includes not only a case where a control command is transmitted to the control deviceand operation control of the target power device is indirectly performed through the control devicebut also a case where operation control of the target power device is performed directly without the control device.

The power adjustment deviceis communicably connected to an external database, and can acquire various kinds of data from the external database. The external databasemay be, for example, a database of a power supplier or a database of a government agency or company that provides weather forecasting.

Next, an example of processing performed by the power adjustment devicewill be described with reference to.are flowcharts showing an example of processing performed by the power adjustment device according to the embodiment. The process shown inis a process subsequent to circled A in.

First, the prediction unitacquires various kinds of data used for predicting demand power from the storage unit(steps Sto S). Specifically, first, the prediction unitacquires power data Efrom the storage unit(step S). The power data Eis a measurement value (actual power value) of the power actually used in the past. The power data Emay be measured, for example, by a smart meter and stored in the external database(for example, a database of a power supplier). The power adjustment devicemay acquire the power data Efrom the external databasein advance, and the storage unitmay store the acquired power data E.is a diagram showing an example of a table of power data. In the example of the table of the power data Eshown in, the date and time and the actual power value are associated with each other.

Then, the prediction unitacquires weather forecast data from the storage unit(step S). The prediction unitacquires, for example, past weather forecast data and weather forecast data for a future target period in which the power supply and demand balance is predicted. The past weather forecast data may be actual weather data in the past. The power adjustment devicemay acquire weather forecast data in advance from the external database(for example, a database of a government agency or company that performs weather forecasting), and the storage unitmay store the acquired weather forecast data.is a diagram showing an example of a table of weather forecast data. In the example of the table of weather forecast data shown in, the date and time, temperature T, dew point temperature T, and the amount of cloud Tare associated with each other. The amount of cloud is divided into 11 levels ranging from 0 to 10, with the closer to 10 the cloudiness.

Next, the prediction unitacquires time data tfrom the storage unit(step S).is a diagram showing an example of a table of time data. In the example of the table of the time data tshown in, the time data tis shown by a value expressed in 1 bit (in this example, “0” or “1”). The time data tshown inis data indicating the hour, but the time data tmay include data indicating the minute.

Then, the prediction unitacquires day-of-the-week data Wfrom the storage unit(step S).is a diagram showing an example of a table of day-of-the-week data. In the example of the table of the day-of-week data Wshown in, the day-of-week data Wis shown by a value expressed in 1 bit (in this example, “0” or “1”).

Then, the prediction unitacquires holiday data H from the storage unit(step S).is a diagram showing an example of a table of holiday data. In the example of the table of the holiday data H shown in, the holiday data H is shown by a value expressed in 1 bit (in this example, “0” or “1”). Hereinafter, the time data t, the day-of-the-week data W, and the holiday data H described above will be collectively referred to as “calendar information”.

Then, the prediction unitacquires people flow data P from the storage unit(step S). The people flow data P is data indicating changes in population over time. The power adjustment devicemay acquire the people flow data P in advance from the external database(for example, a database of a government agency or company that holds the people flow data P), and the storage unitmay store the acquired people flow data P. In the present embodiment, as shown in, an area to which power is supplied by the power systemis divided into a plurality of zones, and the people flow data P is acquired for each zone. In the example shown in, the area is divided into an “industrial zone” where factories are located, a “low-rise building zone” where low-rise buildings are located, a “mixed building zone” where factories, low-rise buildings, and high-rise buildings are located together, a “dense low-rise building zone” where low-rise buildings are densely located, a “high-rise building zone” where high-rise buildings are located, and an “other building zone” where other buildings are located. Each zone may be divided based on latitude and longitude.

is a diagram showing an example of a table of people flow data in the industrial zone.is a diagram showing an example of a table of people flow data in the low-rise building zone.is a diagram showing an example of a table of people flow data in the mixed building zone.is a diagram showing an example of a table of people flow data in the dense low-rise building zone.is a diagram showing an example of a table of people flow data in the high-rise building zone.is a diagram showing an example of a table of people flow data in the other building zone. In each of the table examples shown in, date and time are associated with the population at that date and time. That is,show the population of each zone over time.

Then, the prediction unitpredicts demand power Ofor the future target period based on the various kinds of data acquired in steps Sto S(step S). The prediction unitmay use a neural network to predict the demand power O. For example, the prediction unitmay predict the demand power Ousing a neural network model that outputs the demand power Owhen power data, weather forecast data, calendar information, and people flow data are input as shown in. In the example shown in, the demand power Ois predicted in units of 30 minutes, the demand power Ofor the next 30 minutes from one hour after is predicted to be 20.32 million kW, and the demand power Ofor the next 30 minutes from one hour and 30 minutes after is predicted to be 20 million kW. The method of predicting the demand power Ois not limited. The prediction unitmay predict the demand power Ousing other prediction models, such as a state transition model.

Then, the prediction unitacquires data of supply power Rfor the future target period from the storage unit(step S). The supply power Ris planned in advance by, for example, a power supplier, and is made public. The power adjustment devicemay acquire the data of the supply power Rin advance from the external database(for example, a database of a power supplier) or the like, and the storage unitmay store the acquired data of the supply power R.is a diagram showing an example of a table of supply power data. In the example of the table of the data of the supply power Rshown in, the target period and the planned supply power Rare associated with each other. In the example shown in, the supply power Rfor 30 minutes from 0:00 on Mar. 1, 2022, is planned to be 12.95 million kW, and the supply power Rfor 30 minutes from 0:30 on the same day is planned to be 12.8 million kW.

Then, the prediction unitpredicts the power supply and demand balance for the future target period, and determines whether or not an abnormality in the supply and demand balance will occur (step S). In the embodiment, the prediction unitdetermines that an abnormality in the supply and demand balance will occur when the demand power Opredicted in step Sis greater than an upper limit value θ(when O>θ) or smaller than a lower limit value θ(when O<θ).

The upper limit value θis, for example, a value obtained by multiplying the supply power Racquired in step Sby a coefficient α. The coefficient α is, for example, a number greater than 1. The case where the demand power Ois greater than the upper limit value θcorresponds to a case where overdemand for power occurs. The lower limit value θis, for example, a value obtained by multiplying the supply power Racquired in step Sby a coefficient β. The coefficient β is, for example, a number smaller than 1. The case where the demand power Ois smaller than the lower limit value θcorresponds to a case where the oversupply of power occurs. The value of the supply power Rused to calculate the upper limit value θand the lower limit value θmay be the maximum value of the supply power Ron the day to which the target period belongs. For example, when the target period is 30 minutes starting at 0:00 on Mar. 1, 2022, the value of the supply power Rused to calculate the upper limit value θand the lower limit value θmay be the maximum value of the supply power Ron Mar. 1, 2022. In addition, the value of the supply power Rused to calculate the upper limit value θand the lower limit value θmay be the value of the supply power Rfor the corresponding target period.

is an example of a table showing demand power, an upper limit value, and a lower limit value. In the table example of, the target period, the demand power Ofor the target period, the upper limit value θ, and the lower limit value θare associated with each other. In the example shown in, the demand power Oin the target period starting from 0:00 on Mar. 1, 2022, is 20.32 million kW, the upper limit value θis αR, and the lower limit value θis βR. Ris the maximum value of the supply power Ron Mar. 1, 2022. When the demand power O“20.32 million kW” is greater than the upper limit value θ“αR”, the prediction unitdetermines that an abnormality in the supply and demand balance (overdemand for power) will occur in the target period starting at 0:00 on Mar. 1, 2022. When the demand power O“20.32 million kW” is smaller than the lower limit value θ“βR”, the prediction unitdetermines that an abnormality in the supply and demand balance (oversupply of power) will occur in the target period starting at 0:00 on Mar. 1, 2022.

When overdemand for power is predicted, the prediction unitevaluates the degree of overdemand for power (upward swing of the demand power O) based on the following Expression (1).

f(O, R) in Expression (1) is an abnormality value, and indicates the degree of abnormality in the supply and demand balance (here, overdemand for power). As shown in the upper expression of Expression (1), the abnormality value f(O, R) when O>θis the difference between the demand power Oand the supply power R. In the case of overdemand, the value obtained by subtracting the supply power Rfrom the demand power Ois the abnormality value f(O, R). As the demand power Oincreases and the supply power Rdecreases, the abnormality value f(O, R) increases and accordingly, the degree of overdemand for power increases. As shown in the lower expression of Expression (1), the abnormality value f(O, R) is 0 when O>θis not satisfied (when the demand power Ois equal to or smaller than the upper limit value θ). The prediction unitfunctions as an abnormality value calculation unit that calculates an abnormality value.

is a graph showing abnormality values when overdemand for power is predicted. In, the demand power Ois shown by a solid line, the supply power Ris shown by a broken line, and the upper limit value θis shown by a dashed-dotted line. As shown in, the abnormality value f(O, R) in a period in which the demand power Ois greater than the upper limit value θis a value obtained by subtracting the supply power Rfrom the demand power O. The abnormality value f(O, R) is equal to the absolute value of the difference between the demand power Oand the supply power R. The supply and demand balance in the period in which the demand power Ois greater than the upper limit θis adjusted by controlling the operation of the target power device. The period in which the supply and demand balance is adjusted by controlling the operation of the target power device is referred to as a “control period h”.

On the other hand, when the oversupply of power is predicted, the prediction unitevaluates the degree of oversupply of power (downward swing of the demand power O) based on the following Expression (2).